Hamilton, however, appears to face stiff competition, and not just from Mercedes team-mate Nico Rosberg, as Red Bull duo Daniel Ricciardo and Sebastian Vettel are threatening to spoil the party.

In glorious sunshine over the principality, Hamilton dazzled with a time of one minute 16.758 seconds as the Briton strapped on the quickest of all of Pirelli's four tyre compounds, the supersofts.

But come the conclusion to the hour-long session, the winner of the last four grands prix was just 0.050secs clear of Ricciardo as Red Bull showed clear signs they can threaten Mercedes' dominance here, as expected.

The reason being is Monaco's twisty streets, with precious little via the way of any discernible straight, require less power than has been necessary at the previous circuits visited so far.

Instead, high downforce is key, and the suggestion has long been Red Bull edges that department over Mercedes.

Third fastest on the timesheet was Rosberg, who appeared destined to go quickest of all two minutes from the end.

The 28-year-old, runner-up to Hamilton in the last four races, was a fraction over a tenth of a second up on the Briton over the first two sectors of the track, only to ease off slightly in the third.

Reigning four-times champion Vettel was down in fourth, 0.426secs adrift, and then beyond that there was a clear gap to Ferrari duo Fernando Alonso and Kimi Raikkonen, 0.670secs and 0.690 secs off the pace respectively.

Sergio Perez, at 0.967secs down in his Force India in seventh, was the only other driver to finish within a second of Hamilton.

The top 10 was completed by Perez's team-mate Nico Hulkenberg and Toro Rosso pair Jean-Eric Vergne and Daniil Kvyat, the latter taking on Monaco for the first time in his entire motorsport career.

The team pairings continued down the order as McLaren duo Kevin Magnussen and Jenson Button were 11th and 12th, the latter 1.5secs down, with Williams team-mates Valtteri Bottas and Felipe Massa 13th and 14th respectively.

At the bottom of the timesheet were Marussia's Max Cilton and Marcus Ericsson in his Caterham, the latter almost four seconds in arrears.